Coking processes are relatively severe cracking operations designed to convert residual hydrocarbon stocks such as vacuum and atmospheric residuals and reduced crudes into gas, naphtha, gas oil and coke.
During these coking processes, gases and vaporized liquids such as tar, light oil and ammonia liquor are produced. These compounds and other higher boiling materials will deposit as tar or tar-like substances on the hot metal surfaces of pipes and transmission lines that carry the effluent gases to other parts of the coking unit. This tar or tar-like substance becomes coke-like as it forms deposits and will ultimately plug the pipe or transmission line. The resulting pluggage results in poor flow and necessarily needs to be removed or cleaned so as to continue efficient operation of the coking process. This cleaning often results in the shut-down of the coker oven.
The present inventor has discovered that certain Mannich reaction products will dissolve this tar and inhibit plugging of the pipes and transmission lines so as to keep the pipelines flowing freely without the need for costly shut-down for cleaning.